WO2000012787A1

WO2000012787A1 - Silicon single crystal wafer, epitaxial silicon wafer, and method for producing them

Info

Publication number: WO2000012787A1
Application number: PCT/JP1999/004652
Authority: WO
Inventors: Masaro Tamatsuka; Ken Aihara; Katsuhiko Miki; Hiroshi Takeno; Yoshinori Hayami
Original assignee: Shin-Etsu Handotai Co., Ltd.
Priority date: 1998-08-31
Filing date: 1999-08-27
Publication date: 2000-03-09
Also published as: TWI227286B; EP1035236A1; KR100588098B1; KR20010031575A; US6478883B1; EP1035236A4

Abstract

A boron heavily-doped silicon wafer, an antimony doped silicon wafer, and a phosphorous doped silicon wafer each used for epitaxial growth, having a low oxygen concentration, easily allowing oxygen deposition in spite of the low oxygen concentration, and having a high gettering ability, and an epitaxial silicon wafer including an epitaxial layer which is grown on a substrate wafer which is any of the doped silicon wafer and has an extremely low heavy metal impurity concentration are produced with high productivity and supplied. The invention provides a boron doped single crystal silicon wafer, an antimony doped single crystal silicon wafer, or a phosphorus doped single crystal silicon wafer having a resistivity of 10 to 100 mΦ.cm and produced by growing a silicon single crystal rod by a Czochralski method while doping it with nitrogen and slicing the rod. The invention also provides an epitaxial wafer having an epitaxial layer on the surface of any of the doped silicon wafers and a method for producing such doped wafers and epitaxial wafer.

Description

Description Silicon single crystal wafers, epitaxial silicon wafers, and methods for their manufacture

Technical field

The present invention relates to an epitaxial silicon single crystal wafer for semiconductor device production with few heavy metal impurities harmful to the reliability of the device existing in the epitaxial layer, and a boron single silicon wafer serving as the substrate thereof. The present invention relates to a crystal wafer, an antimony-silicon single-crystal wafer, a Lind-silicon single-crystal wafer, and methods for producing these. Background art

Epitaxial silicon single crystal wafers have long been used as wafers for producing individual semiconductors, bipolar ICs, and the like because of their excellent properties. MOSLSI is also widely used in microprocessor unit flash memory devices because of its excellent soft error and latchup characteristics. In addition, the demand for epitaxial silicon single crystal wafers is increasing to reduce DRAM reliability failure due to so-called Grown-in defects introduced during silicon single crystal manufacturing. ing.

However, the presence of heavy metal impurities on the epitaxial silicon single crystal wafer used in such semiconductor devices may cause the semiconductor devices to have poor characteristics. Particularly clean degree heavy metal impurity concentration 1 X 1 0 ¹ required for the leading edge of the device. It is considered to be less than atoms / cm ^2, and heavy metal impurities present on the silicon wafer must be reduced as much as possible.

According to recent research, even though such an epitaxial wafer is used, depending on the conditions of the epitaxial process and the epitaxial film thickness, the Grown-in defect existing on the surface of the substrate wafer after the epitaxial growth. It has been pointed out that the effect of crystallization becomes apparent (Kimura et al., Journal of the Japanese Association for Crystal Growth Vol.24 No.5 p.444, 1997). In particular, antimony-doped N-type substrates used for low-resistance devices (hereinafter referred to as antimony-doped silicon single-crystal wafers) have an atomic radius of antimony that is larger than that of silicon. Therefore, the density of G row-in defects is higher than that of a normal boron-doped P-type substrate (hereinafter referred to as a boron-silicon single crystal wafer). This was a problem because the effect of rown-in defects was very large compared to other substrates.

Gettering technology is becoming increasingly important as one of the technologies to reduce such heavy metal impurities. Conventionally, epitaxial silicon single crystal wafers for logic devices have been manufactured using boron-silicon single crystal wafers with a high gettering effect and ultra-high boron with a resistivity of less than 1 ππιΩ'cm. Ρ ^{τ +} type substrate (hereinafter referred to as ultra high boron silicon single crystal substrate) is used as the substrate for epitaxy growth and has a resistivity of less than 1 ΟπιΩ'cm. The device yield is higher than when a Ρ ⁺ type substrate with a high boron concentration of 1 1 Οπι Ω.cm or less (hereinafter referred to as a high boron-doped silicon single crystal layer 18) is used as the substrate wafer. Was obtained. However, since the ultra-high boron doped silicon single crystal wafer has a very high boron concentration, there is a problem that the boron impurity in the substrate, which is called auto-doping, jumps out into the gas phase and is taken into the epitaxial growth layer again. Occurs.

As a countermeasure against such auto doping, there is a method of performing epitaxy growth under reduced pressure atmosphere, or a method of applying a CVD oxide film on the back surface of the substrate as a sealing material. In doing so, there was a problem that all of them led to lower productivity and higher costs.

Therefore, it was conceived to use a high-polon-doped silicon single-crystal wafer, which does not require any countermeasures against auto-doping, as a substrate wafer for epitaxy growth. However, gettering of high boron mono-silicon single crystal with low oxygen concentration is segregation type gettering by polon atoms, and copper and nickel gettering is compared with relaxation type gettering by oxygen precipitates. There is a problem that gettering ability is low for heavy metal impurities such as.

—However, conventionally, the production of epitaxial silicon single crystal wafers for CCDs has An N-type substrate doped with phosphorus (hereinafter referred to as a "lin-doped silicon single crystal wafer") or an N-type substrate such as antimony-p-silicon single crystal wafer is used as a substrate wafer for epitaxy growth. Had been. However, these N-type substrates have a problem that oxygen precipitation is less likely to occur as compared with a polysilicon single crystal wafer. Such a lack of gettering ability due to a lack of oxygen precipitation on the N-type substrate is a fatal problem in devices such as CCDs that are sensitive to crystal defects caused by heavy metal impurities.

In particular, in the case of an antimony-doped silicon single crystal wafer, when a silicon single crystal rod doped with antimony is grown by the Czochralski method, the oxygen concentration in the latter half of the growth of the single crystal rod having a high antimony concentration is increased. However, it is very difficult to maintain a high oxygen concentration by evaporating antimony oxide. As a result, the oxygen concentration was reduced, so that oxygen precipitation of the silicon wafer cut from this site was suppressed, and the gettering ability required for device manufacturing could not be obtained.

In order to obtain the same amount of oxygen precipitation as boron boron silicon single crystal wafers in antimony silicon silicon single crystal silicon wafers, compared to boron silicon silicon single crystal wafers. There has been a problem that a long-term oxygen precipitation heat treatment is required, leading to a decrease in productivity.

For example, in the case of a single-crystal silicon single crystal wafer, a first stage heat treatment at a high temperature of 110 ° C. or higher, which is called IG heat treatment, and a second stage heat treatment at about 600 ° C. to 700 ° C. As the third stage of the precipitation nucleation heat treatment, oxygen precipitate formation heat treatment at about 100 ° C. is performed for several hours.

On the other hand, to increase the oxygen precipitation of these high boron silicon single crystal wafers, antimony-doped silicon single crystal wafers and Lind silicon single crystal wafers, it is necessary to increase the oxygen concentration of the wafer. When this is achieved, oxygen precipitation is promoted and the time required for such heat treatment can be reduced, but the amount of oxygen precipitation in the wafer becomes excessive and the deformation of the wafer and the wafer This can cause problems such as reduced strength. In addition, when an epitaxial layer is formed on the surface of these silicon single crystal wafers, harmful effects due to outward diffusion of impurity oxygen in the epitaxial layer are obtained. There is a problem that various defects occur to adversely affect semiconductor device characteristics. Disclosure of the invention

The present invention has been made in view of such problems, and is directed to a high boron-doped silicon single crystal wafer, an antimony silicon single crystal wafer, and a phosphorus-doped silicon single crystal wafer. Therefore, despite the fact that the oxygen concentration in the substrate is suppressed to a level that does not cause problems such as deformation of the wafer and a decrease in the strength of the wafer, silicon is easily deposited in oxygen and has a high gettering ability. The main purpose is to produce and supply an epitaxial silicon single crystal wafer with extremely low concentration of heavy metal impurities in an epitaxial layer grown by using the wafer as a wafer for the substrate with high productivity. .

The present invention for solving the above-mentioned problems is directed to a silicon single crystal wafer doped with a dopant, comprising: an oxygen precipitate or an oxidation-induced stacking fault density after a heat treatment for precipitation of the silicon single crystal wafer. There 1 XI 0 ⁹ pieces / wherein the cm ³ or more de - a silicon single crystal © E one doped with dopant Ha.

The good sea urchin, a silicon single crystal Ueha doped with de one pan DOO, oxygen precipitates or oxidation induced stacking fault density after the precipitation heat treatment of該Shi Li Gong monocrystalline © E one tooth is 1 XI 0 ⁹ pieces Silicon single crystal wafers having a cm ³ or more have a high gettering effect regardless of the type of dopant, and these wafers are used as epitaxy silicon single crystal wafers. If it is used for the substrate wafer, a high-quality epitaxial silicon single crystal wafer can be obtained.

Further, the present invention for solving the above-mentioned problem provides a boron-doped silicon single crystal wafer having a resistivity of l O m Q'cm or more and 100 mΩcm or less,

The oxygen concentration in the boron-doped silicon single crystal wafer is not more than 16 ppma (JEIDA: Japan Electronic Industry Development Association standard), and the oxygen precipitate or oxidation-induced stacking fault density after the heat treatment for precipitation is 1 X 1 is a boron-doped silicon single crystal © E one cog, characterized in that at 0 ⁹ cm ³ or more.

As described above, a boron single-crystal silicon wafer having a resistivity of 10 mΩ · cm or more and 100 mΩ · cm or less, wherein the boron-doped silicon single crystal wafer Oxygen precipitates with a low oxygen concentration of 16 ppma or less but oxygen precipitates or oxidized and melted stacking faults after precipitation heat treatment of 1 × 10 ⁹ / cm ³ or more Doped silicon single crystal wafers have a high gettering ability against heavy metal impurities such as copper and nickel, and the oxygen concentration in the wafers is low, so that the wafers may be deformed or the strength of the wafers may be insufficient. It is possible to prevent snarling.

Further, if such a boron-doped silicon single crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer, harmful oxygen due to outward diffusion of impurity oxygen in the epitaxial layer can be obtained. Epitaxial silicon single crystal wafers with no defects, high gettering effect, and extremely low heavy metal impurity concentration in the semiconductor device fabrication layer can be obtained with high productivity. The above-mentioned problem of the automatic mapping can also be solved.

The present invention also provides a boron-silicon single crystal wafer having a resistivity of 10 mΩcm to 100 mΩcm,

The boron-doped silicon single-crystal wafer is obtained by slicing a silicon single-crystal rod grown by doping nitrogen by the Chiyo-Kralski method. This is a single crystal crystal wafer.

As described above, a boron-doped silicon single crystal wafer having a resistivity of 10 mΩ · cm or more and 100 mΩ · cm or less, wherein the boron-doped silicon single crystal wafer is Chiyo-Kralski If silicon monocrystal rods grown by doping with nitrogen by the method are sliced, oxygen precipitation is promoted by the presence of nitrogen in the bulk part of the wafer. Therefore, even if the oxygen concentration in the substrate is low enough not to cause problems such as deformation of the wafer or reduction in the strength of the wafer, the substrate has a high gettering effect. Become.

Furthermore, when such a boron-doped silicon single-crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer, impurities due to a dopant in the epitaxial layer can be obtained. Thus, an epitaxial silicon single crystal wafer having a high gettering effect and a very low heavy metal impurity concentration can be obtained with high productivity. In this case, the boron-doped silicon single crystal wafer can have an oxygen concentration of 16 ppma or less.

If the oxygen content is 16 ppma or less as described above, the risk of deformation of the wafer and the decrease in the strength of the wafer are further reduced, and the formation of crystal defects in the boron single-crystal silicon wafer is suppressed. Thus, the formation of oxygen precipitates on the surface layer of the wafer can be prevented. Therefore, when the epitaxial layer is formed on the wafer surface, there is no adverse effect on the crystallinity of the epitaxial layer. On the other hand, since oxygen precipitation is promoted by the presence of nitrogen in the bulk portion, the gettering effect can be sufficiently exhibited even with such low oxygen.

Further, the present invention for solving the above-mentioned problem is directed to an antimony-polysilicon single crystal wafer, wherein the density of crystal defects on the surface of the antimony-silicon single crystal wafer is 0.1 / cm2. An antimony-doped silicon single crystal wafer characterized by having a size of not more than cm ² .

As described above, an antimony-doped silicon single-crystal wafer having a crystal defect density of 0.1 cm ² or less on the surface of the antimony-doped silicon single-crystal wafer is: This is a silicon single crystal wafer in which the density of grown-in defects on the wafer surface is extremely small as compared with the conventional antimony silicon single crystal wafer. Therefore, if such an antimony-silicon single-crystal wafer is used as a substrate for manufacturing an epitaxial wafer, an epitaxial silicon single-crystal wafer having a high-quality epitaxy layer can be obtained. I can get one.

Further, the present invention is antimony Dopushiri con single crystal © E - A c, oxygen precipitates or oxidation induced electromotive stacking fault density after the precipitation heat treatment of the en Chimondo one psiri con single crystal Ueha is 1 X 1 0 ⁹ pieces An antimony-p-silicon single crystal wafer having a Z cm of ³ or more.

As described above, the antimony-doped silicon single crystal wafer has an oxygen precipitate or oxidation-induced laminar defect density of 1 × 10 ⁹ after the heat treatment for precipitation of the antimony-doped silicon single crystal wafer. Since the antimony-doped silicon single crystal wafer having the number of pieces / cm ³ or more has an extremely high gettering ability, the density of heavy metal impurities on the wafer surface is high. It becomes a silicon single crystal wafer with extremely low degree. Therefore, when such an anti-monitor silicon single crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer, an epitaxial silicon wafer having a high-quality epitaxy layer can be obtained. A single crystal wafer can be obtained.

Furthermore, the present invention relates to an antimony-doped silicon single crystal wafer, wherein the density of crystal defects on the surface of the antimony-doped silicon single crystal wafer is 0.1 Zcm ² or less, and antimony-doped silicon single crystal © Eha, wherein the oxygen precipitates or oxidation induced stacking fault density after the heat treatment is 1 X 1 0 ⁹ pieces / cm ³ or more.

As described above, in the antimony-doped silicon single crystal wafer, the density of crystal defects on the surface of the antimony-doped silicon single crystal wafer is 0.1 Zcm ² or less, and after the precipitation heat treatment. antimony-doped silicon single crystal © E one tooth oxygen precipitates or oxidation induced stacking fault density of 1 X 1 0 ⁹ pieces / "cm ³ or more, G rown of Ueha table surface - the density of in defects, conventional This is a silicon single crystal silicon wafer that is extremely small compared to antimony silicon silicon single crystal wafers, and has extremely high gettering ability, so the heavy metal impurity density on the wafer surface is extremely low. Therefore, such an antimony-doped silicon single crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer. Thus, an epitaxial silicon single crystal wafer having an extremely high quality epitaxial layer can be obtained.

The present invention also relates to an antimony-doped silicon single-crystal wafer, wherein the antimony-doped silicon single-crystal wafer is grown by nitrogen doping by the Chiyo-Kralski method. An antimony silicon single crystal wafer characterized by being obtained by slicing a silicon single crystal rod.

Thus, an antimony-doped silicon single-crystal wafer, which is obtained by slicing a silicon single-crystal rod grown by doping with nitrogen by the Czochralski method. If so, the density of large row-in defects with large wafer surface size will be significantly reduced due to the effect of nitrogen. In the bulk part of the wafer, oxygen precipitation is caused by the presence of nitrogen. As the concentration of oxygen in the substrate is relatively low so as not to cause problems such as {deformation of the wafer} and reduction of the strength of the wafer, high gettering can be achieved by short-time heat treatment. It has a rolling effect.

Furthermore, if such an antimony-p-silicon single-crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer, the number of large row-in defects on the surface of the substrate wafer is small. However, the adverse effect on the epitaxial layer is extremely small, a high gettering effect is obtained by a short-time heat treatment, and the concentration of heavy metal impurities in the epitaxial layer can be significantly reduced. Therefore, an epitaxy silicon single crystal wafer having an extremely high quality epitaxy layer can be obtained with high productivity.

In this case, the oxygen concentration of the antimony-p-silicon single-crystal wafer is set to 20 ppma (JEIDA: Japan Electronics Industry Development Association Standard) or less.

As described above, if the oxygen content is lower than 20 ppma, there is no need to worry about deformation of the wafer and decrease in wafer strength. In addition, crystal defects in the antimony-doped silicon single crystal wafer are considered. The formation of oxygen precipitates can be suppressed, and the formation of oxygen precipitates on the surface layer of the wafer can be prevented. Therefore, when an epitaxial layer is formed on the wafer surface, the crystallinity of the epitaxial layer is not adversely affected. On the other hand, in the bulk part, the precipitation of oxygen is promoted by the presence of nitrogen, so that the gettering effect can be sufficiently exhibited even in such low oxygen content.

Further, the present invention for solving the above-mentioned problem is directed to a phosphorus-doped silicon single crystal wafer having an oxygen concentration of 18 ppma (JEI DA: Japan Electronic Industry Development Association). (Specification) This is a single-crystal silicon single-crystal wafer characterized by having an oxide precipitate or oxidation-induced stacking fault density after precipitation heat treatment of 1 × 10 ⁹ or more Zcm ³ or more.

As described above, in the case of the silicon single crystal wafer, the oxygen concentration in the silicon single crystal wafer is not more than 18 ppma even though the oxygen concentration is low or low. Oxygen precipitate thin silicon oxide single crystal wafers with an oxygen precipitate or oxidation-induced stacking fault density after precipitation heat treatment of 1 × 10 ⁹ / cm ³ or more are: It has high gettering ability even for short-time heat treatment for heavy metal impurities such as copper and nickel, and the oxygen concentration in the wafer is low. Can be prevented from becoming insufficient.

Furthermore, when such a line of doped silicon single crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer, harmful defects due to outward diffusion of impurity oxygen are generated in the epitaxial layer. It is possible to obtain an epitaxial silicon single crystal wafer having a high gettering effect and a very low heavy metal impurity concentration with high productivity by a short heat treatment without any heat treatment.

The present invention also relates to a silicon-doped silicon single-crystal wafer, wherein the silicon-doped silicon single-crystal wafer is grown by doping nitrogen by the Chioklarski method. A single-crystal silicon single crystal wafer characterized by being obtained by slicing a silicon single crystal rod.

As described above, a single-crystal silicon single-crystal wafer is a silicon single-crystal wafer grown by doping nitrogen with the Chiral Clarke method. If the crystal rod is obtained by slicing, the oxygen concentration in the substrate is promoted by the presence of nitrogen in the pulp portion of the wafer, so that the oxygen concentration in the substrate will be affected by the deformation of the wafer and the strength of the wafer. Even if the concentration is relatively low so as not to cause a problem such as a decrease in the temperature, a high gettering effect can be obtained by a short-time heat treatment.

Furthermore, if such a phosphorus-doped silicon single crystal wafer is used as a substrate wafer for manufacturing an epitaxial wafer, it has a high gettering effect by a short heat treatment and has a very heavy metal impurity concentration. A low epitaxial silicon single crystal wafer can be obtained with high productivity.

In this case, the oxygen concentration of the single-crystal silicon single crystal wafer can be set to 18 ppmm or less.

As described above, if the oxygen content is below 18 ppma, the risk of wafer deformation and reduction of wafer strength is further reduced. The formation of crystal defects in the wafer can be suppressed, and the formation of oxygen precipitates on the surface layer of the wafer can be prevented. Therefore, when the epitaxial layer is formed on the wafer surface, the crystallinity of the epitaxial layer is not adversely affected. On the other hand, since oxygen precipitation is promoted by the presence of nitrogen in the bulk portion, the gettering effect can be sufficiently exhibited even with such low oxygen.

Further, when growing a silicon single crystal by doping nitrogen, the nitrogen concentration of the silicon single crystal substrate should be 1 XI 0 ¹⁰ to 5 X ^{10 15} atoms / cm ^3. Is preferred.

This is, nitrogen by the Ri Siri Konwe of size in one tooth large G rown - together and to inhibit the formation of in defects, to impart an effect to sufficiently promote oxygen ^{precipitation, 1 X 1 0 1 ° atoms} / it to the cm ³ or more is desirable and, in order to Uni by do not interfere with the single crystal of silicon single crystal definitive in chiyo Kurarusuki one method is preferably set to ⁵ XI 0 ¹ 5 atoms m ³ or less Because.

Further, it is preferable that the silicon single crystal wafer has been subjected to a heat treatment at a temperature of 900 ° C. to the melting point of silicon.

As described above, if the silicon single crystal wafer is subjected to a heat treatment at a temperature of 900 ° C. to the melting point of silicon or less, nitrogen and oxygen on the surface of the silicon single crystal wafer are diffused outward. Thus, the crystal defects on the wafer surface layer are extremely small. Further, when a high-temperature heat treatment such as formation of an epitaxy layer is performed thereafter, the precipitation nucleus does not dissolve and the precipitation does not occur, and the wafer has a sufficient gettering effect.

Further, the present invention is an epitaxial silicon single crystal wafer, characterized in that an epitaxial layer is formed on a surface portion of the silicon single crystal wafer of the present invention. This is an epitaxial silicon single crystal wafer.

As described above, the epitaxial silicon single crystal wafer having the epitaxial layer formed on the surface layer of the silicon single crystal wafer 18 of the present invention has a desired resistance value because it has no problem of auto-doping. In addition to having a high quality epitaxy layer having the following characteristics, the productivity is high and the oxygen concentration in the substrate is suppressed to a level that does not cause problems such as deformation of the wafer and reduction in the strength of the wafer. Nevertheless, it has a high gettering effect on heavy metals such as copper and nickel, and becomes an epitaxial silicon single crystal wafer with an extremely low heavy metal impurity concentration.

In addition, the present invention relates to a resin material having a resistivity of not less than 10 mΩcm and not more than 100 mΩcm In the method of manufacturing a silicon single crystal wafer,

To grow silicon single crystal rods doped with nitrogen by doping boron by the Czochralski method, slice the silicon single crystal rods, and process them into silicon single crystal wafers. A method for producing a boron-doped silicon single crystal wafer.

As described above, in the method for manufacturing a boron-silicon single crystal wafer having a resistivity of 1ΟπιΩ′cm or more and 1ΟππΩΩcm or less, boron is doped by the Chiyo-Kralski method and nitrogen is added. Then, a silicon single crystal rod is grown, and the silicon single crystal rod is sliced and processed into a silicon single crystal wafer to produce a boron single-crystal silicon wafer.窒素 Since oxygen precipitation is promoted by the presence of nitrogen in the bulk part of the aerial wafer, the getter is high even if the oxygen concentration in the substrate is such that it does not cause problems such as ゥ deformation of the aerial ゃゥ reduction of the aerial strength. It is possible to manufacture a polysilicon single crystal wafer having a ring effect.

Furthermore, if the polon-doped silicon single crystal wafer manufactured by such a method is used as a substrate for manufacturing an epitaxial wafer, it is possible to prevent impurities from being taken into the epitaxial layer due to single doping. Thus, an epitaxial silicon single crystal wafer having a high gettering effect and an extremely low heavy metal impurity concentration can be obtained with high productivity.

In this case, the concentration of oxygen contained in the single crystal rod can be reduced to 16 ppma or less.

In this case, the gettering effect can be sufficiently exhibited without adversely affecting the crystallinity of the epitaxial layer.

Further, the present invention provides a method for producing an antimony-doped silicon single crystal wafer, comprising: growing a silicon single crystal rod doped with antimony by the Cjochralski method and also doped with nitrogen; Characterized by being processed into silicon single crystal wafers by slicing.

—This is the manufacturing method of c.

As described above, in the method of manufacturing an antimony-doped silicon single crystal wafer, antimony is doped by the Tycho-Kralski method and nitrogen is also doped. A silicon single crystal rod is grown, and the silicon single crystal rod is sliced and processed into a silicon single crystal wafer to produce an antimony silicon single crystal wafer. Due to this effect, the density of Grown-in defects on the wafer surface is significantly reduced. In addition, since oxygen precipitation is promoted by the presence of nitrogen in the bulk portion of the wafer, the oxygen concentration in the substrate causes problems such as deformation of the wafer and reduction in the strength of the wafer. Even with such a relatively low concentration, an antimony-doped silicon single crystal wafer having a high gettering effect can be manufactured by a short-time heat treatment.

Furthermore, if the antimony-p-silicon single-crystal wafer manufactured by such a method is used as a substrate for manufacturing a epitaxial wafer, the Grown-in defect on the surface of the substrate wafer can be improved. Has very little adverse effect on the epitaxy layer, has a high gettering effect by short-time heat treatment, and can significantly reduce the concentration of heavy metal impurities in the epitaxy layer, resulting in extremely high quality epitaxy. An epitaxial silicon single crystal wafer having a layer can be obtained with high productivity.

In this case, the concentration of oxygen contained in the single crystal rod can be reduced to 20 ppma or less.

Further, the present invention provides a method of manufacturing a silicon single crystal wafer having a silicon single crystal rod doped with nitrogen and doped with nitrogen by a Czochralski method. A method for producing a silicon single crystal wafer comprising growing a silicon single crystal rod and processing it into a silicon single crystal wafer.

As described above, in the method of manufacturing a silicon single crystal wafer, a silicon single crystal rod in which the silicon is doped by nitrogen and the nitrogen is doped by the Chiyokuralski method is grown. If a silicon single crystal rod is sliced and added to a silicon single crystal wafer to produce a silicon single crystal silicon wafer, oxygen is reduced due to the presence of nitrogen in the bulk part of the silicon wafer. Oxygen precipitation is relatively unlikely because precipitation is promoted Even if the substrate is a single crystal silicon wafer doped with silicon, and the oxygen concentration in the substrate is such that it does not cause problems such as deformation of the wafer or reduction in the strength of the wafer, heat treatment for a short time Thus, a single-crystal silicon single crystal wafer having a high gettering effect can be manufactured.

Furthermore, if the silicon single crystal wafer produced by such a method is used as a substrate wafer for producing an epitaxial wafer, a high gettering time can be obtained by a short heat treatment. It is possible to obtain an epitaxial silicon single crystal wafer having a high quality epitaxy layer having an extremely low concentration of heavy metal impurities and having a high concentration of heavy metal impurities with high productivity.

In this case, the concentration of oxygen contained in the single crystal rod can be made 18 ppma or less.

By doing so, the gettering effect can be sufficiently exhibited without adversely affecting the crystallinity of the epitaxial layer.

Further, in this case, when growing a silicon single crystal rod doped with nitrogen by the Chiyoklarski method, the concentration of nitrogen doped into the single crystal rod is set to 1 × 10 ^{1 Q} to 1 × ^{10 15} atoms / cm ³ is preferable, and a heat treatment is preferably applied to the silicon single crystal wafer at a temperature of 900 ° C. to the melting point of silicon or lower.

In this way, if a silicon single crystal wafer is manufactured, it can be used as a substrate for epitaxial growth with high gettering ability, few surface defects, and excellent characteristics. Suitable silicon single crystal wafers can be manufactured.

Further, according to the present invention, in a method for producing an epitaxial silicon single crystal wafer, a silicon single crystal wafer is produced by the method for producing a silicon single crystal wafer according to the present invention. A method of manufacturing an epitaxial silicon single crystal wafer, comprising forming an epitaxial layer on a surface portion of the silicon single crystal wafer.

As described above, in the method for manufacturing an epitaxial silicon single crystal wafer, a silicon single crystal wafer is manufactured by the above-described method for manufacturing a silicon single crystal wafer, and the silicon single crystal wafer is manufactured. If an epitaxial layer is formed on the surface layer of the wafer, the effect of Grown-in defects on the substrate wafer surface on the epitaxial layer is extremely small.- The oxygen concentration in the substrate can be reduced. Problems such as deformation of Even if it is suppressed to the extent that it does not occur, since the heavy metal has a high gettering effect by a short heat treatment, the concentration of heavy metal impurities in the epitaxial layer can be significantly reduced, and high quality An epitaxial silicon single crystal wafer having an epitaxial layer can be manufactured with high productivity.

As described above, in the present invention, by using a nitrogen-doped silicon wafer as a substrate of an epitaxial silicon single crystal wafer, a high boron-doped silicon single crystal wafer having a low oxygen concentration is used.アンチ Even antimony dopants and line-doped silicon single crystal wafers, which are difficult to precipitate oxygen, have a high gettering ability because they are easy to precipitate oxygen, and when epitaxial growth is performed on the wafer surface. Can produce high-quality epitaxial silicon single crystal wafers with low defect density and heavy metal impurity concentration in the epitaxial layer with high productivity and easily. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a result diagram showing the measurement results of the oxygen precipitate defect density of wafers by the OPP method after the heat treatment for depositing oxygen precipitates in Example 1 and Comparative Example 1. FIG. 2 is a result diagram showing the measurement results of the crystal defect density on the wafer surface before and after the epitaxial growth in Example 2 and Comparative Example 2 using a particle counter.

FIG. 3 is a result diagram showing the measurement results of the oxygen precipitate defect density of wafers by the OPP method after the heat treatment for precipitating oxygen precipitates in Example 2 and Comparative Example 2. FIG. 4 is a result diagram showing the measurement results of the oxygen precipitate defect density of wafers by the OPP method in Example 3 and Comparative Example 3. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail, but the present invention is not limited thereto.

The present invention relates to a boron-doped silicon single crystal wafer having a resistivity of 1 抵抗 πιΩ · cm or more and 10 1πιΩ · cm or less, or an antimony-doped silicon single crystal wafer or a Lind manufactured by the CZ method. One silicon single crystal wafer, low Obtain silicon single crystal wafers with high oxygen concentration and high oxygen precipitates or oxidation-induced stacking fault density, especially with the technology of doping nitrogen during crystal growth, to produce epitaxial silicon single crystal wafers. The substrate is used for wafers, so that the epitaxial layer does not generate harmful defects due to outward diffusion of impurity oxygen, has a high gettering effect, and has an extremely low concentration of heavy metal impurities. The inventors have found that wafers can be manufactured with high productivity and low cost, and have scrutinized various conditions to complete the present invention.

In other words, it has been pointed out that dropping nitrogen into a silicon single crystal promotes the aggregation of oxygen atoms in the silicon and increases the concentration of oxygen precipitates (T. Abe and H. Takeno , Mat. Res. So Symp. Proc, Vol. 262, 3, 1992) _{= The} second effect is that the process of agglomeration of oxygen atoms shifts from homogeneous nucleation to heterogeneous nucleation with impurity nitrogen as nuclei. It is believed that there is.

Therefore, if nitrogen is doped when growing a silicon single crystal by the Chiyo-Kralski method, a silicon single crystal having a high oxygen precipitate concentration and a silicon single crystal wafer can be obtained by processing the silicon single crystal. . By growing an epitaxial layer using the silicon single crystal substrate as a substrate, a boron oxide single crystal single crystal substrate with a low oxygen concentration and an antimony silicon single crystal substrate that is originally difficult to deposit oxygen can be obtained. A high oxygen precipitate density can be obtained even with a mono-doped silicon single crystal wafer, and as a result, an epitaxial layer having a very low heavy metal impurity density can be grown. Furthermore, since the oxygen concentration in the wafer can be lowered, there is no problem such as ゃゥ deformation of the wafer ゃゥ reduction of the wafer strength, and no adverse effect of impurity oxygen on the epitaxal layer is caused. .

The silicon single crystal wafer manufactured by doping nitrogen during the growth of the silicon single crystal in this manner has a doping amount of not less than 10 mΩ · cm in terms of resistivity. High quality because it has a high gettering effect even if it is doped with antimony that is less than 0 mΩ. In addition, it is possible to form an epitaxial layer, and it is not necessary to take measures against auto-doping, thereby improving not only the quality of the epitaxial silicon single crystal wafer but also the productivity and cost. Can also be expected. In the present invention, a method for growing a silicon single crystal rod doped with boron and doped with boron by the Czochralski method is described, for example, in Japanese Patent Application Laid-Open No. 60-251190. Good according to known methods, such as:

In other words, in the Chiyo-Kralski method, a seed crystal is brought into contact with a melt of a polycrystalline silicon raw material contained in a quartz crucible, and is slowly pulled up while being rotated, and the silicon single crystal rod having a desired diameter is rotated. In this method, a polycrystalline silicon raw material in which polon is doped is placed in advance in a quartz crucible, and a nitride is placed in the quartz crucible. By injecting nitrogen or setting the atmosphere gas to an atmosphere containing nitrogen, nitrogen can be doped into the pulled crystal. At this time, the nitrogen doping amount in the crystal can be controlled by adjusting the amount of the nitride, the concentration of the nitrogen gas, the introduction time, and the like.

In this way, when growing a single crystal rod by the Chiyo-Kralski method, by introducing nitrogen, it is possible to reduce the large-sized Grown-in defects to be introduced and to reduce the amount of silicon. It promotes the coagulation of oxygen atoms in the concrete and can increase the concentration of oxygen precipitates. This method does not require slowing down the pulling speed that is conventionally performed to reduce Grown-in defects, and is a method that can be easily implemented using conventional manufacturing equipment. Silicon single crystals can be manufactured with high productivity without the need for additional equipment.

Conventionally, in the case of a high boron single-crystal silicon wafer having a resistivity of 1ΟπιΩ'cm or more and 100 mΩ-cm or less, an ultra-high concentration porosity of less than 1 1πιΩ-cm is used. Oxygen precipitation is suppressed as compared with a single-crystal silicon wafer, and in the case of a single-crystal silicon wafer and a single-crystal silicon wafer. On the other hand, oxygen precipitation did not occur easily as compared with silicon monocrystal silicon wafers, and the gettering ability required for device fabrication could not be obtained.

In particular, in the case of antimony-doped silicon single crystal wafers, when growing a silicon single-crystal rod with antimony doped by the Czochralski method, the oxygen concentration in the latter half of the grown single-crystal rod with a high antimony concentration is as follows: It is very difficult to maintain a high oxygen concentration due to the evaporation of antimony oxide, and as a result, the oxygen concentration becomes extremely low, so that oxygen precipitation of silicon wafers cut from this site is suppressed. I In other words, the gettering ability required for device manufacturing could not be obtained.

On the other hand, for these wafers, if the oxygen concentration in the wafer is increased to solve this problem, the wafer will be deformed or the wafer strength will be reduced, and if an epitaxial layer is formed on the wafer surface, In this case, defects occurred due to outward diffusion of impurity oxygen into the epitaxial layer, resulting in deterioration of characteristics. However, by doping nitrogen into a silicon single crystal as in the present invention, the gettering ability required for device fabrication can be obtained without increasing the oxygen concentration.

Doping nitrogen into the silicon single crystal promotes the aggregation of oxygen atoms in the silicon and increases the concentration of oxygen precipitates, as described above, because the aggregation process of oxygen atoms starts from uniform nucleation. This is considered to be due to the shift to heterogeneous nucleation with impurity nitrogen as nuclei.

Thus, the concentration of doping nitrogen causes sufficient heterogeneous nucleation, 1 × 10 ¹ . It is preferable to set to atoms / cm ³ or more. As a result, the concentration of the oxygen precipitate can be sufficiently increased. On the other hand, if the nitrogen concentration exceeds the solid solubility limit of ⁵ × 10 ⁵ atoms / cm ³ in the silicon single crystal, single crystallization of the silicon single crystal itself may be hindered. It is preferred not to exceed this concentration.

Further, in the present invention, since the concentration of oxygen precipitates is high even at a low oxygen concentration, when growing a silicon single crystal rod doped with nitrogen by the Chiochralsky method, the oxygen concentration contained in the single crystal rod is increased. Low and low oxygen concentrations of 16 ppma or less when boron is doped, 20 ppma or less when antimony is doped, and 18 ppma or less when phosphorus is doped. Can be.

When the oxygen concentration in the silicon single crystal is set to the above value or less, defects such as oxygen precipitates, which lower the crystallinity of the epitaxial layer, are almost completely formed on the silicon single crystal wafer surface. Therefore, it is possible to prevent adverse effects on the crystallinity of the epitaxial layer grown on the surface of the silicon single crystal wafer. On the other hand, in the bulk portion, the precipitation of oxygen is promoted by the presence of nitrogen, so that the gettering effect can be sufficiently exhibited even with low oxygen.

When growing silicon single crystal rods, lower the oxygen concentration contained to the above range. The method used may be a conventionally used method. For example, the above oxygen concentration range can be easily obtained by means such as a decrease in the number of rotations of the crucible, an increase in the flow rate of the introduced gas, a decrease in the atmospheric pressure, and a control of the temperature distribution and convection of the silicon melt. In this way, in the Chiyo-Kralski method, boron, antimony, or phosphorus is doped and a desired concentration of nitrogen is doped, and a silicon containing a large concentration of crystal defects and a desired concentration of oxygen. A single crystal rod is obtained. According to the usual method, the wafer is sliced with a cutting device such as an inner peripheral blade slicer or a wire saw, and then processed into a silicon single crystal wafer through processes such as chamfering, lapping, etching, and polishing. Of course, these steps are only listed as examples, and there may be various other steps such as washing, heat treatment, and the like. I have.

Next, it is preferable to subject the obtained silicon single crystal wafer to a heat treatment at a temperature of 90 ° C. to the melting point of silicon before performing epitaxial growth. By performing this heat treatment before forming the epitaxial layer, nitrogen on the surface of the silicon single crystal wafer can be diffused outward.

The out-diffusion of nitrogen on the surface of the silicon single crystal wafer is due to the oxygen precipitation promoting effect of nitrogen, which causes oxygen to precipitate on the surface layer of the silicon single crystal wafer and the formation of defects based on this. This is to prevent subsequent adverse effects on the epitaxy layer.

In this case, the diffusion rate of nitrogen in silicon is much higher than that of oxygen, and the heat treatment ensures that nitrogen on the surface can be diffused outward. As a specific heat treatment condition, the heat treatment is preferably performed in a temperature range of 900 ° C. to the melting point of silicon, more preferably, 110 ° C. to 1200 ° C.

By performing the heat treatment in such a temperature range, nitrogen in the silicon single crystal layer can be sufficiently diffused outward, and oxygen can also be diffused outward at the same time. Thus, it is possible to almost completely prevent the generation of defects due to oxygen precipitates in the above, and to prevent the crystallinity of the epitaxial layer from being adversely affected.

In addition, if the above-mentioned heat treatment is not performed before the epitaxial growth and a high-temperature heat treatment is directly applied for the epitaxial growth, the oxygen precipitate nuclei are dissolved, and thereafter, There is a concern that the gettering effect cannot be obtained due to insufficient precipitation even by the heat treatment of the above.However, if the above heat treatment is performed before the high-temperature heat treatment of the epitaxial growth, A sufficient gettering effect can be obtained at the time of layer formation, and an epitaxial silicon single crystal wafer having an extremely low heavy metal impurity concentration can be obtained.

In addition, as a side effect, oxygen precipitates in the bulk of the wafer grow further and induce stacking faults (BSFs), resulting in stronger gettering. In some cases, it is effective.

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Example 1)

A large number of raw materials obtained by adding a predetermined concentration of boron to a 24-inch diameter quartz crucible by the CZ method so that the resistivity is lOm Q'cm or more and 100 mΩcm or less. A crystalline silicon is charged, and a silicon wafer having a silicon nitride film is charged and melted together with the raw material polycrystalline silicon to form a single-crystal rod having a diameter of 8 inches, a P type, and an orientation of 100>. Was pulled up at a normal pulling rate of l. O mmZmin. In addition, when pulling the crystal, the crucible rotation was controlled so that the oxygen concentration in the single crystal became 14 to 16 ppma (JEIDA).

The nitrogen concentration was 2 to 7 × 10 ¹⁴ atoms / cm ^{3 as} calculated by the segregation coefficient. When the oxygen concentration of the single crystal rod was measured by the gas fusion method, it was confirmed that the oxygen concentration was 14 to 16 ppma.

From the single crystal rod obtained here, a wafer is cut out using a wire saw, chamfered, wrapped, etched, and mirror-polished to obtain an 8-inch diameter silicon single crystal mirror surface wafer. Four sheets were produced. The resistivity of the four silicon single crystal wafers was measured to be about 14 to 17 πιΩ′cm, which was within the range expected from the amount of boron added.

Before forming an epitaxial layer on two of the four silicon single crystal wafers, heat treatment at a temperature of 150 ° C. was performed to remove nitrogen from the wafer surface. Spread out. Of these two silicon single crystal wafers, one is at 110 ° C. and the other is at 110 ° C. and has a thickness of 6 / zm. Conepitaxial layer was grown. The epitaxy growth reactor is of a leaf-to-leaf type, and the heating method is a lamp heating method. By introducing a S i HC l ₃ + H ₂ This was allowed to Epitakisharu grow silicon on boron-doped silicon single crystal © E one tooth.

In order to measure the gettering ability of the obtained epitaxial wafer, heat treatment was performed at 800 ° C for 4 hours in an N ₂ gas atmosphere and then in an O ₂ gas atmosphere. Heat treatment was performed at 1000 ° C. for 16 hours to precipitate oxygen precipitates. Thereafter, the gettering effect of these epitaxial silicon single crystal wafers was evaluated by the oxygen precipitate concentration in the bulk of the silicon wafer.

The measurement of the oxygen precipitate concentration was performed by an OPP (Optical Precipitate Profiler) method. This OPP method is based on the application of a Normalski type differential interference microscope. First, a laser beam emitted from a light source is separated into two mutually orthogonal beams of 90 ° linearly polarized light with different phases by a polarization prism. Inject from the mirror side. At this time, when one beam crosses the defect, a phase shift occurs, and a phase difference occurs with the other beam. Defects are detected by detecting this phase difference using a polarization analyzer after passing through the back surface of the wafer.

Figure 1 shows the measurement results. Here, the plot shown on the right side of FIG. 1 shows the oxygen precipitate defect density of a wafer having a nitrogen drop amount of 2 to 7 × 10 ¹⁴ atoms / cm ³ , and a circular plot Indicates a case where the epitaxial growth was performed at 117 ° C., and a triangular plot indicates the oxygen precipitate defect density when the epitaxial growth was performed at 110 ° C. According to Fig. 1, the wafer grown epitaxially on the surface of the boron-doped silicon single crystal wafer doped with nitrogen has an oxygen concentration of 14 regardless of the presence or absence of the heat treatment before the epitaxial growth. Despite being as low as ~ 16 ppma, the same high oxygen precipitate density is exhibited when epitaxial growth is performed at either temperature, indicating a high gettering effect. . Comparing the presence / absence of heat treatment before epitaxial growth, it is clear that the gettering effect is even greater with heat treatment. The crystallinity of the epitaxial layer was very good because of the low oxygen concentration. Furthermore, at this level of boron doping, no auto-doping measures are required. Therefore, improvement in productivity can be expected.

(Comparative Example 1)

Pull up a boron-doped silicon single crystal rod with a diameter of 8 inches, P-type, orientation>100>, oxygen concentration of 14 to 16 ppma, in the same manner as in the example except that nitrogen is not dropped. Was. Then, two silicon single crystal mirror-finished wafers having a diameter of 8 inches were produced from this single crystal rod in the same manner as in the example. Resistivity of the two silicon single crystal Ueha also the two as in Example about 1 4-1 7 ₁ 11 0 '(; it was 111.

Then, in the same manner as in the embodiment except that the heat treatment for outward diffusion of nitrogen was not performed, one of the two silicon single crystal wafers was at 117 ° C and the other was at 113 ° C. A 6 μπι thick silicon epitaxial layer was grown at a temperature of 0 ° C.

Then, similarly to the example, oxygen precipitates were deposited on the obtained epitaxial wafer by heat treatment, and the getters of these epitaxial silicon single crystal wafers were obtained by the Ο method. The ring effect was evaluated by the oxygen precipitate concentration in the bulk of the silicon wafer.

The measurement results are shown in FIG. Here, the plot shown on the left side of Fig. 1 shows the oxygen precipitate defect density of the wafer without nitrogen doping, and the circular plot shows the case where epitaxial growth was performed at 117 ° C. The triangular plot shows the oxygen precipitate defect density when epitaxial growth was performed at 110 ° C.

As shown in Fig. 1, wafers grown epitaxially on the surface of boron-doped silicon single crystal wafers without nitrogen doping have a low oxygen concentration of 14 to 16 ppma. It can be seen that the density of oxygen precipitates is similarly low and the gettering effect is low when epitaxy is performed at either temperature.

(Example 2)

Using a CZ method, a quartz crucible having a diameter of 24 inches is charged with a raw material polycrystalline silicon to which a predetermined concentration of antimony is added, and a silicon wafer having a silicon nitride film together with the raw material polycrystalline silicon is charged. It was charged and melted, and a single-crystal rod of 8 inches in diameter, N-type, and orientation of 100> was pulled up at a normal pulling rate of 1 · O mmZmin. When the crystal was pulled, the crucible rotation was controlled so that the oxygen concentration in the single crystal was 20 ppma (JEI DA) or less. In addition, this In the pulling of the single crystal rod, two single crystal rods were pulled with different nitrogen doping amounts.

When the nitrogen concentrations at the tails of the two single crystal rods were estimated by the calculated values based on the segregation coefficient, they were 1.0 X 10 ¹⁴ atoms / cm ³ and 5.0 X 10 ¹⁴ atoms / cm ³ , respectively. It was. When the oxygen concentration of the single crystal rod was measured by the gas fusion method, it was confirmed that the oxygen concentration of both rods was 10 to 20 ppma.

From the two single crystal rods obtained here, wafers were cut out using a wire saw, chamfered, wrapped, etched, and mirror polished to obtain a silicon single crystal mirror wafer with a diameter of 8 inches. One single crystal rod was manufactured from two single rods, for a total of four. The resistivity of the four silicon single crystals was measured to be about 7 to 25 mO · cm, which was within the range expected from the amount of doped antimony.

Prior to forming an epitaxial layer on the surface of these silicon single crystal wafers, a heat treatment at a temperature of 110 ° C. was applied to diffuse nitrogen on the wafer surface outward.

Further, in order to measure the crystal defect density on the wafer surface before the epitaxial growth, these four silicon single crystal wafers were sufficiently cleaned, and the crystal defect density on the wafer surface was measured. The measurement was performed using one tickle counter.

Of the four silicon single crystal wafers cut from these two silicon single crystal rods, one of the two silicon wafers cut from the same single crystal rod was 120 At 0 ° C, the other was grown at a temperature of 112 ° C with a silicon epitaxial layer with a thickness of 6 μm. The epitaxy growth reactor was of a leaf-to-leaf type, and the heating method was a lamp heating method. By introducing a S i HC 1 ₃ + H ₂ This was allowed to Epitakisharu grow silicon on anti Mondo one psiri con single crystal © E one tooth.

In order to measure the gettering ability of the obtained epitaxial wafers, each wafer was subjected to a heat treatment at 800 ° C. for 4 hours in an N ₂ gas atmosphere. A heat treatment was performed at 1000 ° C. for 16 hours in a ₂ gas atmosphere to precipitate oxygen precipitates. Thereafter, the gettering effect of these epitaxial silicon single crystal wafers was evaluated by the oxygen precipitate concentration in the silicon wafer. The measurement of this oxygen precipitate concentration This was performed by the OPP method.

On the other hand, in order to measure the effect of crystal defects on the surface of the substrate wafer on the epitaxial layer, the crystal defect density on the surface of these epitaxial silicon single crystal wafers after the growth of the epitaxial layer was measured. Each was measured using a particle counter as particles having a size of 0.13 / im or more.

First, the results of measuring the crystal defect density before and after epitaxial growth are shown in FIG. Here, the plot shown in the center of FIG. 2 shows the crystal defect density on the wafer surface with a nitrogen drop amount of 1.0 × 10 ¹⁴ atoms / cm ³ , and the plot shown on the right The graph shows the crystal defect density on the wafer surface with a nitrogen doping amount of 5.0 × 10 ¹⁴ atoms m ³ . The circular plot shows the crystal defect density before epitaxy growth, and the triangular plot shows the crystal defect density after epitaxy growth. These figures show the average values of two PA-8s with the same nitrogen doping amount.

According to FIG. 2, epitaxial growth is performed in both the case where the nitrogen doping amount is 1.0 X 10 ¹⁴ atoms / cm ³ and the nitrogen doping amount is 5.0 X 10 ¹⁴ atoms / cm ^3. It can be seen that the crystal defect density on the front and rear wafer surfaces is extremely low, less than 0.1 / cm ² .

Next, the measurement results of the oxygen precipitate density after the oxygen precipitation heat treatment are shown in FIG. Here, the plot shown in the center of FIG. 3 shows the oxygen precipitate density of the wafer with the nitrogen drop amount of 1.0 × 10 ¹ atoms / cm ³ , and the plot shown on the right shows the plot. The graph shows the oxygen precipitate density of a wafer with a nitrogen doping amount of 5.0 X 10 ¹⁴ atoms / cm ³ . The circular plot shows the density of oxygen precipitate defects when epitaxy was performed at 1200 ° C, and the triangular plot shows the density of oxygen precipitate defects when epitaxy was performed at 125 ° C. .

From Fig. 3, it can be seen that the wafer grown by epitaxy on the surface of an antimony-doped silicon single crystal wafer doped with nitrogen has a medium oxygen concentration of 10 to 20 ppma despite its medium oxygen concentration. However, when the epitaxial growth was performed at either temperature, the density of oxygen precipitates was similarly high, indicating that the gettering effect was high. Furthermore, the gettering heat treatment time required for manufacturing the epitaxial silicon single crystal wafer of this example was about the same as that when the boron-doped silicon single crystal wafer was used as the substrate wafer. Only need to be done and productivity can be expected to improve. (Comparative Example 2)

An antimony-doped silicon single crystal rod having a diameter of 8 inches, an N-type, an orientation of <100>, and an oxygen concentration of 20 ppm or less was pulled in the same manner as in the example except that nitrogen was not dropped. Then, two silicon single crystal mirror wafers having a diameter of 8 inches were produced from this single crystal rod in the same manner as in the example. The resistivity of each of the two silicon single crystal wafers was about 7 to 25 πιΩ′cm as in the example.

Then, in the same manner as in the example except that the heat treatment for out-diffusion of nitrogen was not performed, the crystal defect density on the surface of the silicon single crystal wafer was measured by a particle counter. Of these two wafers, one is 120. The other was grown by silicon epitaxial growth with a thickness of 6 μm at a temperature of 115 ° C.

Oxygen precipitates are deposited on the obtained epitaxial wafer by heat treatment, as in the example, and the gettering effect of these epitaxial silicon single crystal wafers is obtained by the OPP method. Was evaluated by the oxygen precipitate concentration in the bulk of the silicon wafer, and the crystal defect density on the wafer surface after the epitaxial growth was measured by a particle counter.

The measurement results of the crystal defect density before and after the epitaxial growth of the wafer of this comparative example are also shown in FIG. Here, the plot shown on the left side of FIG. 2 shows the crystal defect density on the surface of the wafer without nitrogen doping. The circular plot shows the crystal defect density before epitaxy growth, and the triangular plot shows the crystal defect density after epitaxy growth. These figures show the average of two wafers.

Figure 2 yo is, nitrogen is not doped antimony de one psiri con single crystal Weha, the crystal defect density both before and after Ueha surface of Nipitakisharu growth has exceeded the 0-five Zc m ^2, nitrogen de one It can be seen that the crystal defect density is much higher than that of the wafer being loaded.

The measurement results of the oxygen precipitate density after the oxygen precipitation heat treatment of the wafer of Comparative Example are also shown in FIG. Here, the plot shown on the left side of FIG. 3 shows the oxygen precipitate density of the wafer without nitrogen doping. The circular plot is for epitaxy growth at 1200 ° C, and the triangular plot is for epitaxy at 125 ° C. The graph shows the oxygen precipitate defect density in the case where the thermal growth was performed.

According to Fig. 3, the epitaxial growth on the surface of an antimony-doped silicon single-crystal wafer not doped with nitrogen showed that the boron-doped silicon single-crystal wafer was used as the substrate wafer. The heat treatment time is about the same as the case of (1), and since the oxygen concentration is medium at 20 ppma or less, the density of oxygen precipitates is similarly low regardless of the temperature at which the epitaxial growth is performed, and the getter It can be seen that the ring effect is low.

(Example 3)

A silicon crucible with a predetermined concentration of phosphorus added to a quartz crucible with a diameter of 18 inches is charged by the CZ method, and a silicon nitride film with a silicon nitride film together with the material polycrystalline silicon. Was charged and melted, and a single-crystal rod having a diameter of 6 inches, N-type, and 100> was pulled up at a normal pulling rate of 1.0 mmZmin. In addition, when pulling the crystal, the crucible rotation was controlled so that the oxygen concentration in the single crystal became Isppma (JEIDA).

When the nitrogen concentration at the tail of this single crystal rod was measured by FT-IR, it was 5.0 × 10 ¹⁴ atoms m ³ . In addition, when the oxygen concentration of the single crystal rod was measured by FT-IR, it was confirmed that the oxygen concentration was 18 ppma.

From the single crystal rod obtained here, a wafer was cut out using a wire saw, chamfered, wrapped, etched, and mirror-polished to produce four silicon single crystal mirror-finished wafers with a diameter of 6 inches. . The resistivity of the four silicon single crystal wafers was measured to be about 5 to 10 Ωcm, which was within the range expected from the doping amount of the added phosphorus. there were.

Before forming an epitaxial layer on two of the four silicon single crystal wafers, heat treatment at 110 ° C for 30 minutes was performed to remove nitrogen from the wafer surface. Was diffused.

Of these two silicon single crystal wafers, one was at 110 ° C. and the other was at 110 ° C. and had a thickness of 20 μm. A silicon epitaxial layer was grown. The epitaxy growth reactor has a susceptor on which the substrate and the wafer are placed in a cylinder-type peruger. The heating method is a radiant heating method. This is S i HC 13 + H. Introduces a single-crystal silicon single crystal ゥ Epitaxially grown silicon on eha.

To measure the getter-ring capacity of E pita press roux er Ha obtained by it this, N ₂ after the heat treatment for 4 hours at O Ri 8 0 0 ° C in a gas atmosphere, 0 ₂ 1 6 hours Ri by the gas atmosphere Heat treatment was performed at 100 ° C. to precipitate oxygen precipitates.

Thereafter, the gettering effect of these epitaxial single crystal wafers was evaluated by the oxygen precipitate concentration in the bulk of the silicon wafer. The measurement of the oxygen precipitate concentration was performed by the OPP method.

Fig. 4 shows the measurement results. Here, the plot shown on the right side of FIG. 4 shows the oxygen precipitate defect density of a wafer with a nitrogen drop amount of 5.0 × 10 ¹⁴ atoms / cm ³ , and a circular plot Indicates a case where the epitaxial growth was performed at 117 ° C., and a triangular plot indicates the oxygen precipitate defect density when the epitaxial growth was performed at 110 ° C. As shown in Fig. 4, the wafer grown epitaxially on the surface of a single-crystal silicon single crystal doped with nitrogen, despite the medium oxygen concentration of 18 ppma, also when performing Epitakisharu growth temperature indicates the 1 XI 0 ⁹ pieces / cm ³ or more high oxygen precipitate density in the same manner, it can be seen that a high getter-ring effect. Comparing the presence or absence of the heat treatment before the epitaxial growth, it can be seen that the gettering effect is even greater with the heat treatment. The crystallinity of the epitaxial layer was very good because of the low oxygen concentration. Furthermore, the precipitation heat treatment time before the epitaxial growth in this embodiment is either no heat treatment at all, or very short compared to the conventional IG heat treatment, and an improvement in productivity can be expected.

(Comparative Example 3)

A single-crystal silicon single-crystal rod having a diameter of 6 inches, an N-type, an orientation of <100> and an oxygen concentration of 18 ppm was pulled up in the same manner as in the example except that nitrogen was not dropped. Then, four silicon single crystal mirror wafers having a diameter of 6 inches were produced from this single crystal rod in the same manner as in the example. The resistivity of each of the four silicon single crystal wafers was about 5 to 10 Ω'cm as in the example.

Two of these four wafers were subjected to an IG heat treatment to further promote oxygen precipitation. That is, first heat treatment was performed at 110 ° C for 30 minutes, then heat treatment for forming precipitate nuclei at 6δ0 ° C was performed for 4 hours, and then oxygen precipitates at 100 ° C were formed. P99 / 04652

27

A heat treatment for 16 hours was applied. Of these two silicon single crystal wafers, one was at 110 ° C and the other was at 110 ° C at a thickness of 20 μηι. The growth of the conepitaxial layer was performed. Then, in the same manner as in the examples, oxygen precipitates were further deposited on the obtained epitaxial wafers by heat treatment, and getters of these epitaxial silicon single crystal wafers were obtained by the Ο method. The ring effect was evaluated by the oxygen precipitate concentration in the bulk of the silicon wafer.

The measurement results are shown in FIG. Here, the plot shown on the left side of Fig. 4 shows the oxygen precipitate defect density of the wafer without nitrogen doping, and the circular plot shows the epitaxial growth at 117 ° C. The triangular plot shows the oxygen precipitate defect density when epitaxial growth was performed at 110 ° C.

According to Fig. 4, wafers grown by epitaxial growth on the surface of a single silicon single crystal without nitrogen were grown without epitaxial heat treatment without IG heat treatment. However, since the oxygen concentration is 18 ppma, which is a medium level, it is understood that the density of oxygen precipitates is low and the gettering effect is low regardless of which temperature the epitaxial growth is performed. Also, when the IG heat treatment is performed for a long time as described above, only the same precipitate density as that obtained when the nitrogen is doped and the heat treatment before the epitaxial growth is not performed can be obtained.

Note that the present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the claims of the present invention. It is included in the technical scope of the invention.

For example, in the present invention, when growing a silicon single crystal rod doped with nitrogen by the Czochralski method, it does not matter whether a magnetic field is applied to the melt or not. The Kralski method includes the MCZ method in which a magnetic field is applied.

In addition, the present invention is not limited to the epitaxial growth by the CVD method, but is also applicable to the case where the epitaxial growth is performed by the MBE method to produce an epitaxial silicon single crystal substrate. Can be applied.

Further, in the above embodiment, the high boron doping concentration and the high boron concentration P99 / 0 5

28

High gettering effect even if doped silicon single crystal wafers or medium / low oxygen concentration antimony silicon single crystal wafers or Lind silicon single crystal wafers Although the wafer having the above-mentioned characteristic has been mainly described in the case where it can be obtained by doping with nitrogen, the present invention is not limited to this, and the resistivity is 10 mΩ′cm or more and 1 μm or more. A high boron-doped silicon single crystal wafer of ΟπιΩ · cm or less, wherein the oxygen concentration in the silicon single crystal wafer is as low as 16 ppma or less, and Oxygen precipitates or oxidation-induced stacking fault densities as high as 1 × 10 ⁹ Zcm ³ or more, or antimony silicon single crystal wafers, and the surface of the silicon single crystal wafers der ones density of crystal defects is small and one Zc m ² or less 0.1 Ri, those oxygen precipitates or oxidation induced stacking defect density after the precipitation heat treatment is often a 1 XI 0 ⁹ or ZCM ³ or more, or a re-emission Dopushiri con Tan'yui crystal Ueha, the silicon co down monocrystalline Ueha in if the oxygen concentration is of medium-low concentration under 1 8 ppma or less, and oxygen precipitates or oxidation-induced product layer defect density after the precipitation heat treatment is 1 X 1 0 ⁹ pieces / cm ³ but higher and often For example, they are included in the scope of the present invention.

Further, the oxygen precipitate or the oxidation-induced stacking fault density of 1 × 10 ⁹ / cm ³ or more referred to in the present invention means that even after the silicon wafer has been subjected to a precipitation heat treatment, it can be used for epitaxial growth. The present invention is also included in the scope of the present invention as long as the above-described oxygen precipitate or oxidation-induced stacking fault density can be obtained similarly when the precipitation heat treatment is performed after the heat treatment.

Claims

The scope of the claims

1. Dopant preparative A de one flop the silicon single crystal © E one wafer, oxygen precipitates or oxidation induced stacking fault density after the precipitation heat treatment of the silicon single crystal Ueha is 1 X 1 0 ⁹ pieces / cm ^A silicon single crystal wafer whose dopant is doped, characterized in that the number is ³ or more.

2. A boron-doped silicon single crystal wafer having a resistivity of 10 mΩ · cm or more and 100 mΩ / cm or less,

The oxygen concentration in the boron silicon single crystal wafer is 16 ppma or less, and the oxygen precipitate or oxidation-induced stacking fault density after the heat treatment for precipitation is 1 × 10 ⁹ cm ³ or more. A boron-doped silicon single crystal wafer characterized in that:

3. A boron-doped silicon single crystal wafer having a resistivity of 1 1 Ω Ω 'cm or more and 1 Ο ππι Ω -cm or less,

The boron single-crystal silicon wafer is obtained by slicing a silicon single-crystal rod grown by doping with nitrogen by a Chiyo-Kralski method. Crystal wafer.

4. The boron-doped silicon single-crystal wafer according to claim 3, wherein the oxygen concentration of the boron-doped silicon single-crystal wafer is 16 ppma or less.

5. An antimony-doped silicon single-crystal wafer, wherein the density of crystal defects on the surface of the antimony-doped silicon single-crystal wafer is 0.1 / cm ² or less. Silicon single crystal wafer.

6. A antimony de one psiri co down monocrystalline © E by one tooth, the antimony Dopushi Li Gong monocrystalline © oxygen precipitates after the precipitation heat treatment of the E one tooth or oxidation induced stacking fault density 1 XI 0 ⁹ pieces Zcm anti Mondo one, characterized in that ^three or more psiri con single crystal Ueha _c

7. An antimony silicon single crystal wafer, wherein the density of crystal defects on the surface of the antimony silicon single crystal wafer is 0.1 cm ² or less, and Oxygen precipitate or oxidation-induced stacking fault density after heat treatment is 1 X 10 ⁹ or more Zcm ³ An antimony-doped silicon single crystal wafer characterized by the above.

8. An antimony-doped silicon single-crystal wafer, wherein the antimony-doped silicon single-crystal wafer is obtained by slicing a silicon single-crystal rod grown by doping with nitrogen by the Czochralski method. An antimony-silicon single crystal wafer characterized by being obtained.

9. The antimony-doped silicon single-crystal wafer according to claim 8, wherein the oxygen concentration of the antimony-doped silicon single-crystal wafer is not more than 20 ppma.

10. Lind-silicon single crystal wafer, wherein the oxygen concentration in the phosphorus-doped silicon single crystal wafer is 18 ppma or less, and oxygen precipitates or oxidation induced substances after the heat treatment for precipitation. Li command one psiri con single crystal © E one tooth, wherein the stacking fault density of 1 X 1 0 ⁹ or cm ³ or more.

1 1. A silicon single-crystal silicon wafer, wherein the single-crystal silicon silicon wafer is a silicon single-crystal rod grown by doping nitrogen by the Chioklarski method. A silicon single crystal wafer obtained by slicing a silicon single crystal.

12. The phosphorus-doped silicon single-crystal layer according to claim 11, wherein the oxygen concentration of the phosphorus-doped silicon single-crystal layer is 18 ppma or less.

1 3. The nitrogen concentration of the silicon single crystal wafer is 1 × 10 ¹ . 55 × ^{10 15} atom / cm ³ , characterized in that it is one of claim 3, claim 4, claim 8, claim 9, claim 11 or claim 12. 2. The silicon single crystal wafer according to item 1.

14. The silicon single crystal wafer has been subjected to a heat treatment at a temperature of 900 ° C. to a melting point of the silicon or lower. The silicon single crystal wafer according to any one of claim 8, claim 9, claim 11, claim 12, and claim 13.

1 5. An epitaxial silicon single crystal wafer, wherein an epitaxial layer is formed on a surface portion of the silicon single crystal wafer according to any one of claims 1 to 14. Epitaxial silicon single crystal © E ¹ Nono ₀

16. In a method of manufacturing a silicon monocrystal silicon wafer having a resistivity of 10 mΩ · cm or more and 100 mΩ · cm or less,

The method is characterized in that a silicon single crystal rod is grown by doping boron and nitrogen with the Czochralski method and then slicing the silicon single crystal rod into a silicon single crystal wafer. A method for producing boron-doped silicon single crystal wafers.

17. The method of growing a silicon single crystal rod doped with nitrogen by the Czochralski method, wherein the concentration of oxygen contained in the single crystal rod is set to 16 ppma or less. 3. The method for producing a polon-doped silicon single crystal wafer according to item 1.

18. In the method of manufacturing an antimony doped silicon single crystal wafer, a silicon single crystal rod doped with nitrogen and doped with nitrogen is grown by the Tycholarski method, and the silicon single crystal rod is sliced. A method for producing an antimony-doped silicon single crystal wafer, which is processed into a silicon single crystal wafer.

19. The growth of a nitrogen-doped silicon single crystal rod by the Czochralski method, wherein the concentration of oxygen contained in the single crystal rod is set to 20 ppma or less. 8. The method for producing the antimony silicon single crystal wafer according to 8.

20. In the method of producing phosphorus-doped silicon single crystal wafers, silicon single crystal rods doped with nitrogen and doped with nitrogen by the Czochralski method are grown, and the silicon single crystal rods are sliced to produce silicon single crystal rods. A method for producing a single-crystal silicon single crystal wafer, which is processed into a single crystal wafer.

21. When growing a silicon single crystal rod doped with nitrogen by the Czochralski method, the concentration of oxygen contained in the single crystal rod is set to 18 ppma or less. Item 20. The method for producing a phosphorus-doped silicon single crystal wafer according to Item 20.

2 2. When nitrogen nurturing doped silicon single crystal rods by the Chiyokurarusuki method, the nitrogen concentration of de one up to the single crystal ^{bar, 1 X 1 0 1 ° ~} 5 X 1 0 1 ^{5 to 5 at} ms / cm ³ , according to any one of claims 16 to 21. The method for producing the silicon single crystal wafer described above.

23. The silicon single crystal wafer is subjected to a heat treatment at a temperature of 900 ° C. to a melting point of the silicon or lower. The method for producing a silicon single crystal wafer described in (1).

24. A method for producing an epitaxial silicon single crystal wafer, comprising: the method for producing a silicon single crystal wafer according to any one of claims 16 to 23; A method for producing an epitaxial silicon single crystal wafer, comprising: producing a wafer; and forming an epitaxial layer on a surface portion of the silicon single crystal wafer.